*{
    user-select: none;
    /* 无法选中，整体感更强 */
}
body{
    background: url(../images/wallpaper.jpg) no-repeat;
    background-size: cover;
    background-attachment: fixed;
}
.login{
    position: absolute;
    top: 50%;
    margin-top: -200px;
    left: 50%;
    margin-left: -200px;
    /* absolute居中的一种方法 */
    background-color: whitesmoke;
    width: 400px;
    height: 450px;
    border-radius: 25px;
    text-align: center;
    padding: 5px 40px;
    box-sizing: border-box;
    /* 这样padding就不会影响大小 */
}

p{
    font-size: 42px;
    font-weight: 600;
}

.user{
    background-color: whitesmoke;
    width: 100%;
    height: 48px;
    margin-bottom: 10px;
    border: none;
    border-bottom: 2px solid silver;
    /* 下面的会覆盖上面的步伐 */
    outline: none;
    font-size: 22px;
}
.btn
{    background-color: whitesmoke;
    width: 100%;
    height: 48px;
    margin-bottom: 10px;
    border: none;
    border-bottom: 2px solid silver;
    /* 下面的会覆盖上面的步伐 */
    outline: none;
    font-size: 22px;
}
.btn{
    background-color: #59c2c5;
    width: 38%;
    height: 48px;
    border-radius: 8px;
    margin-top: 40px;
    font-size: 28px;
    font-weight: 600;
    color: white;
}
.btn:hover{
    background-color: #59c2a0;
}
input[type=checkbox]{
    cursor: pointer;
}
input[type=checkbox]:checked:before {
    content: "\2713";
    background: #fffed5;
    text-shadow: 1px 1px 1px rgba(0, 0, 0, .2);
    font-size: 20px;
    text-align: center;
    line-height: 8px;
    display: inline-block;
    width: 13px;
    height: 15px;
    color: #00904f;
    border: 1px solid #cdcdcd;
    border-radius: 4px;
    margin: -3px -3px;
    text-indent: 1px;
}
input[type=checkbox]:before {
    content: "\202A";
    background: #ffffff;
    text-shadow: 1px 1px 1px rgba(0, 0, 0, .2);
    font-size: 20px;
    text-align: center;
    line-height: 8px;
    display: inline-block;
    width: 13px;
    height: 15px;
    color: #00904f;
    border: 1px solid #cdcdcd;
    border-radius: 4px;
    margin: -3px -3px;
    text-indent: 1px;
}